How does thickness affect magnetic coupling in Ti-based MXenes

The magnetic nature of Ti2C, Ti3C2, and Ti4C3 MXenes is determined from periodic calculations within density functional theory and using the generalized gradient approximation based PBE functional, the PBE0 and HSE06 hybrids, and the on-site Hubbard corrected PBE+U one, in all cases using a very tig...

Descripción completa

Detalles Bibliográficos
Autores: García-Romeral, Néstor, Morales García, Ángel, Viñes Solana, Francesc, Moreira, Ibério de Pinho Ribeiro, Illas i Riera, Francesc
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/200465
Acceso en línea:https://hdl.handle.net/2445/200465
Access Level:acceso abierto
Palabra clave:Carburs
Nitrurs
Ferromagnetisme
Carbides
Nitrides
Ferromagnetism
id ES_cd1703dba49857fcd18f7b6f3aaeb0d5
oai_identifier_str oai:recercat.cat:2445/200465
network_acronym_str ES
network_name_str España
repository_id_str
spelling How does thickness affect magnetic coupling in Ti-based MXenesGarcía-Romeral, NéstorMorales García, ÁngelViñes Solana, FrancescMoreira, Ibério de Pinho RibeiroIllas i Riera, FrancescCarbursNitrursFerromagnetismeCarbidesNitridesFerromagnetismThe magnetic nature of Ti2C, Ti3C2, and Ti4C3 MXenes is determined from periodic calculations within density functional theory and using the generalized gradient approximation based PBE functional, the PBE0 and HSE06 hybrids, and the on-site Hubbard corrected PBE+U one, in all cases using a very tight numerical setup. The results show that all functionals consistently predict a magnetic ground state for all MXenes, with spin densities mainly located at the Ti surface atoms. The analysis of solutions corresponding to different spin orderings consistently show that all functionals predict an antiferromagnetic conducting ground state with the two ferromagnetic outer (surface) Ti layers being antiferromagnetically coupled. A physically meaningful spin model is proposed, consistent with the analysis of the chemical bond, with closed shell, diamagnetic, Ti2+ like ions in inner layers and surface paramagnetic Ti+ like centers with one unpaired electron per magnetic center. From a Heisenberg spin model, the relevant isotropic magnetic coupling constants are extracted from an appropriate mapping of total energy differences per formula unit to the expected energy values of the spin Hamiltonian. While the numerical values of the magnetic coupling constants largely depend on the used functional, the nearest neighbor intralayer coupling is found to be always ferromagnetic, and constitutes the dominant interaction, although two other non-negligible interlayer antiferromagnetic terms are involved, implying that the spin description cannot be reduced to NN interaction only. The influence of the MXene thickness is noticeable for the dominant ferromagnetic interaction, increasing its value with the MXene width. However, the interlayer interactions are essentially due to the covalency effects observed in all metallic solutions which, as expected, decay with distance. Within the PBE+U approach, a U value of 5 eV is found to closely simulate the results from hybrid functionals for Ti2C and less accurately for Ti3C2 and Ti4C3.Royal Society of Chemistry2023202320232023info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersion12 p.application/pdfhttps://hdl.handle.net/2445/200465Articles publicats en revistes (Ciència dels Materials i Química Física)reponame:Recercat. Dipósit de la Recerca de Catalunyainstname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)InglésReproducció del document publicat a: https://doi.org/10.1039/d3cp01617jPhysical Chemistry Chemical Physics, 2023, vol. 25, p. 17116-17127https://doi.org/10.1039/d3cp01617jcc-by-nc (c) García-Romeral, Néstor et al., 2023http://creativecommons.org/licenses/by-nc/3.0/es/info:eu-repo/semantics/openAccessoai:recercat.cat:2445/2004652026-05-29T05:05:01Z
dc.title.none.fl_str_mv How does thickness affect magnetic coupling in Ti-based MXenes
title How does thickness affect magnetic coupling in Ti-based MXenes
spellingShingle How does thickness affect magnetic coupling in Ti-based MXenes
García-Romeral, Néstor
Carburs
Nitrurs
Ferromagnetisme
Carbides
Nitrides
Ferromagnetism
title_short How does thickness affect magnetic coupling in Ti-based MXenes
title_full How does thickness affect magnetic coupling in Ti-based MXenes
title_fullStr How does thickness affect magnetic coupling in Ti-based MXenes
title_full_unstemmed How does thickness affect magnetic coupling in Ti-based MXenes
title_sort How does thickness affect magnetic coupling in Ti-based MXenes
dc.creator.none.fl_str_mv García-Romeral, Néstor
Morales García, Ángel
Viñes Solana, Francesc
Moreira, Ibério de Pinho Ribeiro
Illas i Riera, Francesc
author García-Romeral, Néstor
author_facet García-Romeral, Néstor
Morales García, Ángel
Viñes Solana, Francesc
Moreira, Ibério de Pinho Ribeiro
Illas i Riera, Francesc
author_role author
author2 Morales García, Ángel
Viñes Solana, Francesc
Moreira, Ibério de Pinho Ribeiro
Illas i Riera, Francesc
author2_role author
author
author
author
dc.subject.none.fl_str_mv Carburs
Nitrurs
Ferromagnetisme
Carbides
Nitrides
Ferromagnetism
topic Carburs
Nitrurs
Ferromagnetisme
Carbides
Nitrides
Ferromagnetism
description The magnetic nature of Ti2C, Ti3C2, and Ti4C3 MXenes is determined from periodic calculations within density functional theory and using the generalized gradient approximation based PBE functional, the PBE0 and HSE06 hybrids, and the on-site Hubbard corrected PBE+U one, in all cases using a very tight numerical setup. The results show that all functionals consistently predict a magnetic ground state for all MXenes, with spin densities mainly located at the Ti surface atoms. The analysis of solutions corresponding to different spin orderings consistently show that all functionals predict an antiferromagnetic conducting ground state with the two ferromagnetic outer (surface) Ti layers being antiferromagnetically coupled. A physically meaningful spin model is proposed, consistent with the analysis of the chemical bond, with closed shell, diamagnetic, Ti2+ like ions in inner layers and surface paramagnetic Ti+ like centers with one unpaired electron per magnetic center. From a Heisenberg spin model, the relevant isotropic magnetic coupling constants are extracted from an appropriate mapping of total energy differences per formula unit to the expected energy values of the spin Hamiltonian. While the numerical values of the magnetic coupling constants largely depend on the used functional, the nearest neighbor intralayer coupling is found to be always ferromagnetic, and constitutes the dominant interaction, although two other non-negligible interlayer antiferromagnetic terms are involved, implying that the spin description cannot be reduced to NN interaction only. The influence of the MXene thickness is noticeable for the dominant ferromagnetic interaction, increasing its value with the MXene width. However, the interlayer interactions are essentially due to the covalency effects observed in all metallic solutions which, as expected, decay with distance. Within the PBE+U approach, a U value of 5 eV is found to closely simulate the results from hybrid functionals for Ti2C and less accurately for Ti3C2 and Ti4C3.
publishDate 2023
dc.date.none.fl_str_mv 2023
2023
2023
2023
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/200465
url https://hdl.handle.net/2445/200465
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Reproducció del document publicat a: https://doi.org/10.1039/d3cp01617j
Physical Chemistry Chemical Physics, 2023, vol. 25, p. 17116-17127
https://doi.org/10.1039/d3cp01617j
dc.rights.none.fl_str_mv cc-by-nc (c) García-Romeral, Néstor et al., 2023
http://creativecommons.org/licenses/by-nc/3.0/es/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv cc-by-nc (c) García-Romeral, Néstor et al., 2023
http://creativecommons.org/licenses/by-nc/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 12 p.
application/pdf
dc.publisher.none.fl_str_mv Royal Society of Chemistry
publisher.none.fl_str_mv Royal Society of Chemistry
dc.source.none.fl_str_mv Articles publicats en revistes (Ciència dels Materials i Química Física)
reponame:Recercat. Dipósit de la Recerca de Catalunya
instname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
instname_str Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
reponame_str Recercat. Dipósit de la Recerca de Catalunya
collection Recercat. Dipósit de la Recerca de Catalunya
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869419779049127936
score 15,812429

Similares en LA Referencia